1. Field of the Disclosure
The present disclosure relates to the manufacture of reclosable packages or bags, particularly manufacturing processes wherein the ends of the zipper need to line up at the fin seal to insure success of the closure. This may be applied to wide mouth openings wherein a long unisex zipper is placed across the width of a film going through a machine, such as a vertical form fill seal machine, to make a pouch. The pouch could be of many styles, including a pillow, gusseted, or quad seal style.
2. Description of the Prior Art
High speed manufacture of reclosable packages is well-developed and very satisfactory for its intended purposes. However, further increases in manufacturing speed and decreases in manufacturing costs are always sought. In particular, some manufacturing processes for reclosable packages including, but not limited to, form fill and seal processes, could benefit from improvements to bring fine adjustment to the alignment of zipper profiles at the fin seal to further decrease any registration tolerances or errors, and further consistently increase the aesthetic appeal of the resulting package. Typical tolerances or errors are on the order of one eighth to one quarter of an inch, and may be as low as one sixteenth of an inch for ease of closure.
The possible misalignment of the zipper location at the fin seal can be induced by such factors as errors in the printing of the film registration marks; errors in the placement of the zipper on the film; errors created by the increased drag caused by the zipper at the fill tube and from the film distance travelled (drag) from the upstream sensor measuring the film registration marks; and errors created by the product flowing intermittently into the fill tube and hitting the pouch bottom creating a standing wave of varying tension around the fill tube.